From 6abe0b375cb4f1b1c0d2986d4fd2ba6329a3c011 Mon Sep 17 00:00:00 2001
From: Matt-Yorkley <9029026+Matt-Yorkley@users.noreply.github.com>
Date: Wed, 12 May 2021 16:31:49 +0100
Subject: [PATCH] Refactor stock levels check in CartController

---
 app/controllers/cart_controller.rb | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/app/controllers/cart_controller.rb b/app/controllers/cart_controller.rb
index edd9e69b6d..e35aedad28 100644
--- a/app/controllers/cart_controller.rb
+++ b/app/controllers/cart_controller.rb
@@ -11,11 +11,7 @@ class CartController < BaseController
       order.cap_quantity_at_stock!
       order.recreate_all_fees!
 
-      variant_ids = order.line_items.pluck(:variant_id)
-
-      render json: { error: false,
-                     stock_levels: VariantsStockLevels.new.call(order, variant_ids) },
-             status: :ok
+      render json: { error: false, stock_levels: stock_levels(order) }, status: :ok
     else
       render json: { error: cart_service.errors.full_messages.join(",") },
              status: :precondition_failed
@@ -24,6 +20,13 @@ class CartController < BaseController
 
   private
 
+  def stock_levels(order)
+    variants_in_cart = order.line_items.pluck(:variant_id)
+    variants_in_request = raw_params[:variants]&.map(&:first) || []
+
+    VariantsStockLevels.new.call(order, (variants_in_cart + variants_in_request).uniq)
+  end
+
   def check_authorization
     session[:access_token] ||= params[:token]
     order = Spree::Order.find_by(number: params[:id]) || current_order